title: Abnormalities in auditory efferent activities in children with selective mutism.
abstract: Two efferent feedback pathways to the auditory periphery may play a role in monitoring self-vocalization: the middle-ear acoustic reflex (MEAR) and the medial olivocochlear bundle (MOCB) reflex. Since most studies regarding the role of auditory efferent activity during self-vocalization were conducted in animals, human data are scarce. The working premise of the current study was that selective mutism (SM), a rare psychiatric disorder characterized by consistent failure to speak in specific social situations despite the ability to speak normally in other situations, may serve as a human model for studying the potential involvement of auditory efferent activity during self-vocalization. For this purpose, auditory efferent function was assessed in a group of 31 children with SM and compared to that of a group of 31 normally developing control children (mean age 8.9 and 8.8 years, respectively). All children exhibited normal hearing thresholds and type A tympanograms. MEAR and MOCB functions were evaluated by means of acoustic reflex thresholds and decay functions and the suppression of transient-evoked otoacoustic emissions, respectively. Auditory afferent function was tested by means of auditory brainstem responses (ABR). Results indicated a significantly higher proportion of children with abnormal MEAR and MOCB function in the SM group (58.6 and 38%, respectively) compared to controls (9.7 and 8%, respectively). The prevalence of abnormal MEAR and/or MOCB function was significantly higher in the SM group (71%) compared to controls (16%). Intact afferent function manifested in normal absolute and interpeak latencies of ABR components in all children. The finding of aberrant efferent auditory function in a large proportion of children with SM provides further support for the notion that MEAR and MOCB may play a significant role in the process of self-vocalization.
authors.affiliation: Department of Communication Disorders, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Chava
authors.initials: C
authors.lastname: Muchnik
authors.forename: Daphne
authors.initials: D
authors.lastname: Ari-Even Roth
authors.forename: Minka
authors.initials: M
authors.lastname: Hildesheimer
authors.forename: Miri
authors.initials: M
authors.lastname: Arie
authors.forename: Yair
authors.initials: Y
authors.lastname: Bar-Haim
authors.forename: Yael
authors.initials: Y
authors.lastname: Henkin
mesh_terms: D000293:Adolescent; D001306:Auditory Pathways / Q000503:physiopathology*; D001308:Auditory Perceptual Disorders / Q000453:epidemiology / Q000503:physiopathology*; D001309:Auditory Threshold / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D017626:Cochlear Nucleus / Q000502:physiology*; D004525:Efferent Pathways / Q000503:physiopathology*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D025461:Feedback, Physiological / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009155:Mutism / Q000453:epidemiology / Q000503:physiopathology*; D009847:Olivary Nucleus / Q000502:physiology*; D015995:Prevalence; D012021:Reflex, Abnormal / Q000502:physiology; D012022:Reflex, Acoustic / Q000502:physiology; D013065:Speech Intelligibility / Q000502:physiology